Carb rejetting question?

I have an 81 KZ550 LTD that I have cafe'd and installed a set of pod filters on. It came with stock 92 and 32 jets. It now idles fine but can't hardly get it to go down the street. Where do I need to begin with jet sizes to correct the problem. I'm a novice with this problem so any help I can get will appreciated!

lhemrick wrote:

I have an 81 KZ550 LTD that I have cafe'd and installed a set of pod filters on. It came with stock 92 and 32 jets. It now idles fine but can't hardly get it to go down the street. Where do I need to begin with jet sizes to correct the problem. I'm a novice with this problem so any help I can get will appreciated!

Question please --- is it known how the bike performed (presumably with the stock air box) before the pods were fitted?

Thinking the reported problem might be something else other than a carb issue.

Good Fortune!

Ran fine! So it has to be a fuel/air mixture problem. I realize that when you change air filter methods and let it breathe better you must increase the fuel delivery, I just need to know where I need to start. I have a set of 105's here but I wonder if thats to much?

Pods will create performance problems unless you are willing to fiddle with the carbs long enough to find the magic combination of ingredients to compensate for the additional airflow. Even then, you may experience issues with rain, high wind, etc. I respectfully suggest you use the search function on this site and review any of the hundreds of postings describing the pros & cons of pods and tuning tips. Nearly everyone who switched to pods is thrilled with the way they perform, and nearly everyone that uses pods on this site knows the secret of making them work as well as the stock airbox. However, you may receive slightly different recommendations as to which jets / needles / clip positions, pods, carb supports, shields, etc. to use. But don’t give up; just keep trying the various combinations that are recommended until you find the perfect setup. Good luck, and be sure to provide feedback on which setup works best as there may be new folks in the future that your feedback will help. Ed

i will be watching this thread closely... i have the same bike and i'm wanting to put pods on. please post your progress...

thanks,

"I know this guy" and he says its not difficult and he knows Kawasaki motorcycles. He says I need to jump up to 102's or 105's from the 92's and see how she acts. He has also suggested that I run a couple of sizes bigger in the center cylinders due to the extra heat. Most race bikes are that way and some production bikes are coming that way stock! Let me have a couple of days to get some changes made and I'll post some results!

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I assume you don't have the stock exhaust, then?

Even with a low restriction exhaust, 105 might be a little too big, but not so big it won't run. You will want more like a 98 to 102 depending on the exhaust. Also the type of pods will make a difference.

If you are using paper Emgo pods, don't oil them.

You will want to get the needle sorted out first, but you may still need to up the pilot to 34 or 37. The rebuild kits will come with stock 32 pilots, so at least you'll have extras if you get the rebuild kits.

The rebuild kits come with an adjustable version of your needle. Your needle is equivalent to the second clip from the top on the adjustable needle. You would likely want to change the clip to the third from the top once you get the new needles.

Change the needles first. There is a trick to it. First, you remove the screw holding the slide arm to the throttle shaft. Make sure you have a good screwdiver that fits perfectly because those may be tight. You do not want to mess up those screws. Put a bit of antiseize on them when you put them back in.

Next, you need to get the right size, long, skinny, philips screwdriver. This is for the small screws holding the slides to the arm. If they are tight, try a long blade driver to loosen them first.

You have to get one of the screws while the slide is down, then the other while the slide is up. Anti-seize the screws.

It looks tricky, but after a few times you'll be a pro at it.

After changing the needles, the bike should at least run.

One other issue is the throttle stop. If it's set too far past where the slide is fully open, the mixture will get too rich at full throttle.

Check this thread for images related to the TK-22
kzrider.com/index.php?option=com_kunena&...ew&catid=3&id=407335

Also, check the plugs and check the gaps. Sometimes when adding the pods, it will breathe more which will be a problem if the gaps are too wide. The gaps will stress out weak coils (or weak igniter) to the point where they could stop sparking. In that case you want new coils, but resetting the gaps may make it run ok temporarily.

lhemrick wrote:

"I know this guy" and he says its not difficult and he knows Kawasaki motorcycles. He says I need to jump up to 102's or 105's from the 92's and see how she acts. He has also suggested that I run a couple of sizes bigger in the center cylinders due to the extra heat. Most race bikes are that way and some production bikes are coming that way stock!

Some of the inline V twins run richer jets in the rear cylinder because it doesn't get as much cool airflow as the front.

When changing the needle position it will require me to sync the carbs? Do I need to set the gaps in the plugs smaller than stock?

lhemrick wrote:

When changing the needle position it will require me to sync the carbs? Do I need to set the gaps in the plugs smaller than stock?

Would suggest using same jet needle clip position in all four carbs, and not a richer clip setting in the middle two carbs. Just my 2 cents.

Technically, changing the clip positions should not affect the existing sync, which is basically to the pilot circuit, and not influenced by the needle jet.

But I would re-sync anyhow, just in case, as the slide heights may have been ever so slightly disturbed when reconnected to the control arms.

Imo, the better practice is to follow FSM's recommendation regarding spark plug gaps.

Good Fortune!

Thanks everyone for the help! I have a manual and a couple of people here locally that I can count on too. This is new territory for me but I always tell my son you'll never learn if you don't try soooooooo hand me my screwdriver! I will keep posted!